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Diffstat (limited to 'libpthread/linuxthreads/spinlock.c')
-rw-r--r--libpthread/linuxthreads/spinlock.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/libpthread/linuxthreads/spinlock.c b/libpthread/linuxthreads/spinlock.c
index 80aeda529..ce970029e 100644
--- a/libpthread/linuxthreads/spinlock.c
+++ b/libpthread/linuxthreads/spinlock.c
@@ -188,10 +188,16 @@ int __pthread_unlock(struct _pthread_fastlock * lock)
WRITE_MEMORY_BARRIER();
again:
- while ((oldstatus = lock->__status) == 1) {
- if (__compare_and_swap_with_release_semantics(&lock->__status,
+ oldstatus = lock->__status;
+ if (oldstatus == 0 || oldstatus == 1) {
+ /* No threads are waiting for this lock. Please note that we also
+ enter this case if the lock is not taken at all. If this wouldn't
+ be done here we would crash further down. */
+ if (! __compare_and_swap_with_release_semantics(&lock->__status,
oldstatus, 0))
- return 0;
+ goto again;
+
+ return 0;
}
/* Find thread in waiting queue with maximal priority */